1. Field of the Invention
The invention relates to a nuclear reactor with a propagation space for core melt, the propagation space being provided with a coolant conduit which leads to a coolant reservoir and which has a valve opening in a temperature-dependent manner.
In a nuclear reactor of the above-mentioned type, which is known from German Published, Non-Prosecuted Patent Application DE 40 41 295 A1, a steel crucible disposed in a reactor pit receiving a reactor pressure vessel has a plurality of inner protective layers, in order to withstand the high temperature of the core melt. A coolant pipe leads in an upper half through a wall of the crucible and a melting plug is located at an end of the coolant pipe which is inside the crucible. Another end of the coolant pipe leads to a coolant reservoir. If core melt escapes from the reactor pressure vessel, it is intercepted directly below the reactor pressure vessel within the reactor pit. If the core melt rises level with an outlet orifice of the cooling conduit, the melting plug is melted open as a result of direct contact or as a consequence of heat radiation. Cooling water is thereby guided in a large quantity onto the surface of the core melt for the direct cooling of the latter. Indirect cooling of the core melt takes place through a cooling system disposed outside the crucible. Direct cooling does not commence until clearly after indirect cooling and leads to a rapid flooding of the crucible, in which case large quantities of cooling water can come into contact with the core melt.